We have shown that a DNA plasmid construct can drive expression of HIV-1 genes in non-human primates, inducing both cellular and humoral immune responses. We now report 15 HIV-infected subjects given the vaccine in a dose-ranging study (30, 100, and 300aeg). Subjects with CD4 cell counts >=500 received 3 intramuscular vaccine doses at 10 week intervals with follow-up for 36 weeks. As of 10/1/96, all 3 dose cohorts have received all 3 doses, and 9 have recently received a +4 months booster, all without evidence of local or systemic clinical toxicity. Neither have CBC, urinalysis, serum creatinine, aldolase, or liver chemistries changed; 3 transient rises in creatine kinase have occurred. None developed antinuclear or antiDNA antibodies. CD4 counts rose >=20% in 2, and fell in 4; CD8 increased >=20% in 3, and fell in 4. Viral load increased by >=0.5 log in 1, and fell by >=0.5 in 1. Dose-related rises in anti-env antibody occurred, as did time-dependent CTL responses to env-expressing target cells. Parameters including cytokine analysis are under study. The vaccine appears safe and capable of inducing specific immune responses to HIV antigens.